1. Field of the Invention
The present invention relates to an ink-jet printer, and more particularly, to a method of and an apparatus for determining an amount of ink using current flowing through a head in an ink-jet printer.
2. Description of the Related Art
A conventional method of informing a user whether a remaining amount of ink used in an ink-jet printer is in short supply will be described below.
First, a controller (not shown) of the ink-jet printer performs a counting operation in response to a head fire pulse that is inputted to a head (not shown). Then, the controller determines whether the remaining amount of the ink is in short supply using a result of the counting operation. For example, when the ink is ejected through a nozzle in response to a “high” logic level of the head fire pulse, the controller performs the counting operation in response to the “high” logic level of the head fire pulse and determines whether the remaining amount of the ink is in short supply, using the result of the counting operation. In this case, the result of the counting operation is accumulated in a memory, and then, if a result of the accumulation reaches a predetermined value, it is warned (indicated) to a user that the ink is in short supply. Here, the predetermined value corresponds to the total number of operations in which ink is ejected through nozzles until the amount of the ink is in short supply.
Likewise, in the related art, it is measured how many times ink ejection through the nozzles is requested, instead of how many times the ink ejection through the nozzles is performed. Also, it is determined whether the ink is in short supply by comparing an accumulated value of the result of measurement (the accumulation) with the predetermined value. Hence, in the conventional method, since the ink may be not ejected through the requested nozzles, a user cannot be precisely informed whether the ink used in the ink-jet printer is in short supply.
Moreover, in the conventional method, it cannot be checked whether ink for each color is in short supply. That is, in the conventional method, it cannot be checked whether the ink for each color, such as cyan, magenta or yellow, is in short supply. It can be checked only whether color ink is in short supply or mono ink is in short supply.